The present invention relates in general to distribution of protected (e.g., licensed) digital content over computer networks such as the Internet, and, more specifically, to making content items available via multiple digital rights management (DRM) systems and methods and to selection of a compatible DRM method for distributing content items from a target server to a client.
When distributing digital, electronic media files that contain copyrighted material, it becomes difficult or impossible to prevent files from being retransmitted and shared among large numbers of users, which thereby threatens the rights of artists and copyright owners. Digital rights management technologies are used to restrict the ability to open (e.g., listen to or view) media files to those who obtain a valid DRM license. Protected files are encrypted prior to distribution using an encryption key and are typically packaged with a key identifier and a network address of a DRM license server where a valid license can be obtained (e.g., by payment of a license fee). The granted license includes a decryption key and may also include various rules or limitations pursuant to which the file can be accessed (e.g., a fixed subscription period or a fixed number of playbacks of the media file).
A variety of DRM systems or methods have been introduced by different developers of DRM technology. Each DRM method has its own unique protocols, signaling methods, encryption algorithms, and media player requirements. The various DRM methods are not compatible with one another, so that unique software applications are required to be installed on the personal computers of the users accessing any particular media files protected by a particular DRM method. One such method is Microsoft® Windows Media® DRM system which uses the Windows Media® Rights Manager and the Windows Media® Player (currently at version 9.0). Another method is the Electronic Media Management System (EMMS) from International Business Machines Corporation. Many content providers of DRM encoded content have adopted proprietary DRM methods requiring proprietary software applications in order to access their content.
Because of the multitude of incompatible DRM methods, a user may be required to install many software applications on their personal computer in order to access content from various content providers. However, many users find it undesirable to install and configure large numbers of similar applications on their computer. Because of the lack of a standardized DRM method, widespread adoption of digital media distribution using DRM technology has been impeded.